Coating apparatus



April 12, 1949.

zsheers-sheet 1 Filed March 2l, 1946 a@ In I|Irh|m o o n ffl. .II.. wir), f. .xm w. e R QN F ||.l|||

April 12, 1949 R. LoBsTElN j COATING APPARATUS 2 Sheets-Sheet 2 Filed March 21, 1946 Patented Apr. l2, 1949 COATING APPARATUS Robert Lobstein, Chicago, lll., assignor of onehalf to Samuel R. Hunter, Chl

cago, Ill.; Florence H. Hunter, admlnistratrix of said Samuel R. Hunter, deceased Application March 21, 1946, Serial No. 6755.937

Claims. l

This invention relates to an apparatus for coating paper and other sheet materials, also a method of coating paper and other sheet materials, and the principal object of this invention is to apply coating liquor to one or both sunfaces of the paper during the process of its manufacture before it is completely dry, whereby the coating liquor will be more thoroughly absorbed by the bres of the paper.

Another object is to obtain a more even and uniform distribution of the coating liquor upon the paper than has been accomplished heretofore.

Another object is to regulate the thickness of the film applied to the paper without changing the specific gravity of the coating liquor.

Another object is to smooth out the film after it has been applied by means of hot and cold rolls, whereby the lm will be uniformly dis-l its original unfinished state to the wet paper.

With these and other objects and advantages in view this invention consists in the several novel features of construction, arrangement and combination of parts,` and the method of coating pa- Iper and other materials hereinafter described and claimed.

The invention is clearly illustrated in the drawings accompanying this specification, in which:

Fig. 1 is a diagrammatic view in side elevation of -a portion of a conventional paper drying machine with the apparatus, forming the subject matter of this specification, interposed between a first set and a second set of drying rolls;

2 two closely spaced driven rolls 8, l, below which is a pair of driven rolls 8, 8, and beside said rolls 8, 9, may be other driven rolls I0. I I or more. The

'Fig'. 2 is a, cross section through a drum and l pan forming part of the apparatus, the line of section being indicated at 2-2 in Fig. 3. and

Fig. 3 is a vertical longitudinal section taken on the line 3-3 of Fig. 2.

Referring to said drawings and rst to Fig. 1, the reference character 4 designates a number of the rst set of drying rolls and 5 designates a number of the second set of drying rolls. These two sets of rolls are spaced apart to enable the apparatus, forming the subject matter of this specification, to be interposed between the two sets of rolls.

Rotatably mounted on suitable supports 3, are

web W of wet paper passes around the first set of rolls I, and then down between the rolls 8, 1, and down between the rolls 8, 8 and II0, II. from which the paper web is fed to the second set of drying rolls 5. One of the rolls 8, 9 and III. Il or more may be heated and the other may be cold.

All of the rolls 6, 1, 8, 8 and I0, II are held in close contact with the paper web, and if desired the oscillatory rolls 9 and II may be pressed toward the companion rolls 8 and I0 by air cylinders I2, I3 containing pistons which are connected by piston rods I4 and I5 with the supporting members I8, I1 for the rolls 9, II. The supporting members I6 and II are pivotally mounted upon the supports 3 as at I8, I9; the axes of the other rolls 6, 1, 8 and I0 may be fixed.

The coating liquor is applied to one or both rolls 6, 1 from pans or other containers 20, suitably supported by the main supports of the apparatus.

The coating liquor may comprise a solution of suitable coating substance such as for example, glue, gelatin, casein, calcium sulphate, resin or varnishes, dissolved in a vehicle of water or oil. However, the coating liquor may comprise any of the standard, conventional coating liquors such as are applied to paper webs for the purpose of rendering them suitable for printing purposes.

Inasmuch as the liquor applying means for both rollsfl, 'I is similar, a description of one will suffice for both.

Rotatably carried by suitable brackets 2|, 22 (see Fig. 3) is a vacuum drum 23. This vacuum drum dips into the coating liquor and transfers a lm'thereof directly upon the roll 1 or by an applicator roll 24 which applies the film of coating liquor to the roll 1, and the roll 'l transfers the film to a wet web W as it passes between the rolls 6, '1. Other smoothing apparatus such as pressure rolls or brushes can be used in connection with the rolls 6, 'I in accordance with the common practice in the art of coating paper.

The vacuum drum is of the usual construction used for vacuum filters. The drum 23 has an outer chambered drum member 25, carried by the side walls 28 of the drum. The outer cylindrical wall 21 of the drum member 25 is perforated, as at 29, and extending about the perforated wall 21 is a cylindrical felt or other separating pad 28 or fine screen mesh. The interior of the drum member 25 is divided into a plurality of air 'chambers 25a by partitions 28a.

Axially disposed within the drum is a cylinder 3l, carried by the side walls 26 of the drum, and the interior of the cylinder 30 is connected to the several chambers 25a in the drum member 25 by pipes or conduits 3l.

Stationariiy mounted within the cylinder 30 is a partition member 32 which divides the interior of the cylinder into a number of individual chambers or compartments 33, 34, 35, 36. The partition member is formed with walls 31, 38, 39, 40, which divide the interior of the cylinder into the several chambers or compartments, said walls radiating from a, central hub 4I. One end of the partition member 32 may be secured to or formed as a part of a head 42 which may be provided with a bearing ange 44 surrounding and having a close nt with the end of the cylinder 30. The other end of the cylinder is closed by a second head 45 secured thereto. The drum may be rotated by a shaft 46, driven from any suitable source of power and having one end secured to the head 45.

A pipe or other conduit 41 leads from the vacuum chamber 33 to a suitable vacuum pump (not shown) and a pipe or other conduit 48 leads from a compressor (not shown) to the compressed air chamber 35. Suitable valves V49, 50 are interposed, respectively, in the pipes or conduits 41, 48, whereby the amount of vacuum in the vacuum chamber 33 may be regulated and whereby the l pressure in the chamber 35 may be controlled.

of the coating liquor through the pad and perforations and into the associated chambers 25a.

When any of the tubes which have been subjected to the inuence of a partial vacuum pass the wall 31, the vacuum is broken inasmuch as air is free to enter through a hole 5l in the head 42, but as soon as any such tube passes the wall 38, pressure is set up in the chamber 35 and in the perforations in the outer wall of the drum and in the pad, and a film of the coating liquor is thereby deposited upon the roll 6 or l directly or by the applicator roll 24 which applies it to the roll 6 or 1 and the latter rolls apply the coating liquor film to the wet paper.

The method of coating paper is carried on by withdrawing quantities of the coating liquor from a container by suction and applying the coating liquor to a roll by compressed air.

From the above it is apparent that a smoother, more uniformly distributed film is deposited upon thepaper and that the thickness of the lm may be regulated by partially opening or closing the valve 49 of the pipe leading to the vacuum pump or by other means so as to increase or decrease the amount of vacuum to which the coating liquor is subjected.

Another possibility to change the thickness of the illm is by lowering or raising the whole vacuum drum into the coating liquor and thus change the quantity of film taken out of the liquor.

The invention has been shown and described in connection with the art of making paper. but it is to be understood that cloth, leather and other 4 sheet materials may be coated with the apparatus.

With the rolls 8, l, i8, Il or more partly heated and partly cold and pressure regulated. it is possible to smooth the film surface and not spoil the lm. Moreover the after calendar maybe dispensed with.

Having thus described my invention it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence, I do not wish to be understood as limiting myself to the exact form. construction, arrangement and combination of parts herein shown and described or usesmentioned.

What I claim as new and desire to secure by Letters Patent is:

l. In apparatus forl applying coating liquor to paper or other sheet material having a pair of closely spaced rolls between which the material is fed, and a pan for containing coating liquor, a vacuum drum for supplying coating liquor to one of said rolls, said vacuum drum dipping into the liquor, and said vacuum drum having a perforated cylindrical wall covered by a porous pad, walls on the internal side of the cylindrical wall forming chambers opening out through the perforated cylindrical wall, an inner cylinder concentric with the axis of the drum, tubes connecting said cylinder with the chambers at the periphery of the drum, stationary partitions in said inner cylinder is drawn into said chambers by vacuum and expelled therefrom by compressed' air.

2. In coating apparatus for coating paper and other sheet material, having a pair of rolls between which a web of paper is fed, an applicator roll contacting with one of said pair of rolls, a rotatable vacuum drum, a pan for containing coating liquor into which the vacuum drum dips said vacuum drum contacting with said applicator roll and having a perforated cylindrical outer face covered by a porous material, and a plurality of chambers opening out through said perforations, an inner cylinder concentric with the axis of the drum, a plurality of tubes connecting said inner cylinder with said chambers, a plurality of stationary partitions dividing said inner cylinder into individual vacuum and compressed air chambers, a valve controlled vacuum pipe opening to the vacuum chamber and a compressed air pipe opening to said compressed air chamber.

3. In a paper coating apparatus having a pair of rolls between which a wet web of paper is fed, an applicator roll contacting with one of `said rolls, and a pan for containing coating liquor, a rotatable vacuum drum `contacting with said applicator roll and having a perforated cylindrical wall and a plurality of chambers opening out through the perforations, said outer cylindrical wall being covered with a porous material, an inner cylinder concentric with the axis-of the drum, a plurality of tubes connecting said inner cylinder with said chambers, a plurality of sta'- tionary partitions dividing said inner cylinder into individual vacuum and compressed air chambers, the tubes in the part of the drum that is passing through the coating liquor establishing communication between the vacuum chamber and the other chambers with which they are connected and the tubes in the part of the drum which is contacted' with the applicator roll establishing communication between the compressed air chamber and the other chambers to which said tubes are connected, a -Vacuum pipe opening to the vacumn chamber and a compressed air pipe opening to the compressed air chamber, and means for controlling the amount of vacuum to which the vacuum chamber is subjected.

4. In a paper coating apparatus having a pair of rolls between which a wet web of paper is fed, an applicator roll contacting with one said pair of rolls, and a pan for containing coating liquor, a rotatable vacuum drum having a .perforated cylindrical outer wall and a plurality of chambers opening out through the perforations, said perforated cylindrical wall being covered by a porous piece of material contacting with said applicator roll, said vacuum drum having an inner cylinder concentric with the axis of the.

drum, a plurality of tubes connecting said inner cylinder with said chambers, a plurality of stationary partitions dividing said inner cylinder into individual vacuum and compressed air chambers, the tubes in the part of the drum which is passing through the coating liquor establishing communication between the vacuum chamber and the other chambers with which the tubes are connected, and the tubes in the part of the drum which is contacted with the applicator roll establishing communication between the compressed air chamber and the other chambers to which said tubes are connected,a vacuum pipe opening to the vacuum chamber and a compressed air pipe ope to the compressed air chamber and a valve in the vacuum pipe for controlling the amount of vacuum to which the vacuum chamber is subjected.

' of stationary partitions dividing said inner cylinder into individual vacuum and compressed air chambers, the tubes in that part of the drum which is passing through the coating liquor establisl'ilng` communication between the vacuum chamber and the otherl chambers with which the tubes are connected, and the tubes in the part of -the drum which is contacted with the applicator rolls establishing communication between the compressed air chamber and the other chambers to which said tubes are connected, a valve controlled vacuum pipe opening vto the vacuum chamber and a compressed air pipe opening to said compressed air chamber.

ROBERT LOBSTE'IN.

REFERENCESv CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 1,253,162 Faber Jan. 8, 1918 1,848,478 Haugh Mar. 8, 1932 1,867,930 Traquair July 19, 1932 1,917,818 Woodworth July 11, 1933 2,199,228 Obenshain Apr. 30, 1940 2,293,125

Y Fanselow Aug. 18, 1942 

